The ability to assess behavior is crucial when investigating animal models of mental retardation and intellectual disabilities. Despite the great importance of studying behavior in animal models of mental retardation, researchers often find it difficult to obtain this information. Investigating behavior requires sufficient training and expensive dedicated equipment. Thus the individual researcher typically cannot establish these procedures on his/her own, and investigators who have the relevant procedures established in their labs are sometimes reticent to enter into collaborations not directly related to their ongoing projects. The Neurobehavior Core has provided BCM-IDDRC investigators a solution to this problem. First, for those investigators interested in learning to perform the behavioral testing themselves, the Core provides training and access to the specialized equipment for behavioral assessments of mutant mice. Second, those investigators more interested in collaborating with the Core (.e.g Drs. Paylor and Spencer) to perform the evaluations have a means to examine their mutant mice without dedicating personnel and time to an aspect of their project that may not necessarily be an initial high priority. It is important to note that investigators are encouraged to perform their own experiments since only a limited number of 'collaborative'projects can be performed each year with the current resources. During the past several years there are approximately 5-7 projects that are performed by the Core as a collaborative service. Using this system, our experience is that most investigators prefer to perform their own behavioral testing.